Some articles on pseudopotential:

Pseudopotential - Atomic Physics
... The pseudopotential is an attempt to replace the complicated effects of the motion of the core (i.e ... non-valence) electrons of an atom and its nucleus with an effective potential, or pseudopotential, so that the Schrödinger equation contains a modified effective potential term instead of the ... The pseudopotential approximation was first introduced by Hans Hellmann in the 1934 ...